Oregon Revised Statutes Occupations and Professions § 701.320

(1) A contractor that enters into a contract to construct a new residential structure or zero-lot-line dwelling, or to sell a new residential structure or zero-lot-line dwelling constructed by the contractor, shall make a written offer to the property owner or original purchaser of the structure or dwelling of a warranty against defects in materials and workmanship for the structure or dwelling. The property owner or original purchaser of the structure or dwelling may accept or refuse the offer of a warranty by the contractor. If a contractor makes the written offer of a warranty before the contractor and the property owner both sign a written construction contract and the property owner refuses the offered warranty, the contractor may withdraw the offer to construct the structure or dwelling.

(2) Subsection (1) of this section does not apply to a residential structure that is a manufactured dwelling as defined in ORS 446.003.